The present invention relates to a boosting mechanism of two-stroke engine, and more particularly to an activating lever disposed with a turbo-propeller in front of an intake port of the combustion chamber of an engine for enhancing the power of the engine. The present invention is applicable to the engines of various kinds of model cars or motorcycles.
It is known that the thermodynamic cycle of the working of an engine is generally composed of four strokes of intake, compression, explosion and exhaustion. Such cycle is employed by most of the cars. However, such four strokes necessitate multi-cylinder engine which needs higher cost and large space.
A two-stroke engine employs single cylinder to accomplish the functions of intake, compression, explosion and exhaustion. These four steps are performed during two-time reciprocation of the piston so that the efficiency is poorer than that of the tour-stroke engine. However, it is easier to increase the power of the engine so as to increase the average working pressure of the working gas. The rear end of the conventional activating lever of the engine is disposed with a small tray formed with a notch for coupling with a crank. After activated, the activating lever has no other function benefiting the intake. Therefore, the two-stroke engine generally employs a crank case for sweeping the gas. In operation of such engine, the lubricant oil in the crank case may be guided into the cylinder to affect the combustion efficiency. Moreover, the crank in the crank case sweeps the gas linearly so that the working gas flows into the combustion chamber in a straightly linear manner. The working pressure value of the gas is not high. Moreover, the gap between the crank and the wall of the crank case is limited by the profile of the crank case so that a sealed state may be hardly achieved. Therefore, when the gas pressure in the combustion chamber is higher than the gas pressure in the crank case, the gas may reversely flow from the combustion chamber through the gap between the crank and the crank case wall to the crank case. As a result, the gas pressure in the combustion chamber can be hardly increased and thus the working efficiency of the engine cannot be enhanced.